1. Field of the Invention
This invention relates to a float control for a switch, in particular, but not exclusively, for use in a coffee making machine with a water reservoir and an electrical throughflow heater, for switching said throughflow heater on and off, depending on the presence of water in said reservoir.
2. Discussion of the Prior Art
A coffee making machine which comprises, in the water path from the reservoir through the throughflow heater to a coffee filter, directly under the water reservoir, a float chamber with a float which when the reservoir is empty occupies such a position that, as a result, a switch breaks the electrical circuit of the throughflow heater, thereby preventing the apparatus from boiling dry, is described in applicant's U.S. Pat. No. 3,619,561 and in the corresponding German Pat. No. 1,926,826. In it, the switch is a stationary mercury switch mounted on the float body.
Although coffee making machines equipped with such mercury switches built-in in the float have functioned excellently in large numbers and for many years, and still do, there are some drawbacks, which the present invention seeks to meet.
Thus the prior float-switch unit is relatively expensive, because high demands are made on the manufacture thereof with regard to tightness and the vacuum level in the mercury switch. Furthermore, when the switch production is put out to contract, it is difficult for the manufacturer of the coffee making machines to check the float-switch unit as to the above aspects before mounting the same.
As, in coffee making machines, among others, one failure to switch off the power supply to the water heater when the water reservoir is empty can already result in damage requiring repair in a workshop, it is an object of the present invention to provide a float control for a mechanical switch that can be arranged at a remote position from a float, and nevertheless can be controlled by the float in a reliable manner.